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vf_paletteuse: fix color cache lookup for Bayer dithering mode.

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To trigger this bug, use `paletteuse=dither=bayer:bayer_scale=0`; you will see
that adjacent pixel lines will use the same dither pattern, instead of being
shifted from each other by 32 units (0x20).

One way to demostrate the bug is:

$ convert -size 64x256 gradient:black-white -rotate 270 grad.png
$ echo 'P2 2 1 255 0 255' > bw.pnm
$ ffmpeg -i grad.png -filter_complex 'movie=bw.pnm,scale=256x1[bw]; [0:v][bw]paletteuse=dither=bayer:bayer_scale=0' gradbw.png

Previously: https://www.rm.cloudns.org/img/uploaded/0bd152c11b9cd99e5945115534b1bdde.png
Now:        https://www.rm.cloudns.org/img/uploaded/89caaa5e36c38bc2c01755b30811f969.png

This was caused by passing inconsistent color vs (a,r,g,b) parameters to
color_get(), and NBITS being 5 meaning actually hitting the same cache node
does happen in this case, but ONLY if bayer_scale is zero.

The fix is passing the correct color value to color_get().

Also added a previous-failing FATE test; image comparison of the first frame:

Previously: https://www.rm.cloudns.org/img/uploaded/d0ff9db8d8a7d8a3b8b88bbe92bf5fed.png
Now:        https://www.rm.cloudns.org/img/uploaded/a72389707e719b5cd1c58916a9e79ca8.png

(on this less synthetic test image, the bug basically causes noise from cache
 hits vs misses)

Tested: FATE passes, which exercises this filter but at the default bayer_scale.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
This commit is contained in:
Rudolf Polzer
2022-01-10 10:25:31 -08:00
committed by Gyan Doshi
parent bca30570d2
commit dcc9454ab9
3 changed files with 81 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
libavfilter/vf_paletteuse.c
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@@ -423,7 +423,8 @@ static av_always_inline int set_frame(PaletteUseContext *s, AVFrame *out, AVFram
const uint8_t r = av_clip_uint8(r8 + d);
const uint8_t g = av_clip_uint8(g8 + d);
const uint8_t b = av_clip_uint8(b8 + d);
const int color = color_get(s, src[x], a8, r, g, b, search_method);
const uint32_t color_new = (unsigned)(a8) << 24 | r << 16 | g << 8 | b;
const int color = color_get(s, color_new, a8, r, g, b, search_method);
if (color < 0)
return color;

3
tests/fate/filter-video.mak
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@@ -59,6 +59,9 @@ fate-filter-paletteuse-nodither: CMD = framecrc -auto_conversion_filters -i $(TA
FATE_FILTER_PALETTEUSE += fate-filter-paletteuse-bayer
fate-filter-paletteuse-bayer: CMD = framecrc -auto_conversion_filters -i $(TARGET_SAMPLES)/filter/anim.mkv -i $(TARGET_SAMPLES)/filter/anim-palette.png -lavfi paletteuse=bayer -pix_fmt bgra
FATE_FILTER_PALETTEUSE += fate-filter-paletteuse-bayer0
fate-filter-paletteuse-bayer0: CMD = framecrc -auto_conversion_filters -i $(TARGET_SAMPLES)/filter/anim.mkv -i $(TARGET_SAMPLES)/filter/anim-palette.png -lavfi paletteuse=bayer:bayer_scale=0 -pix_fmt bgra
FATE_FILTER_PALETTEUSE += fate-filter-paletteuse-sierra2_4a
fate-filter-paletteuse-sierra2_4a: CMD = framecrc -auto_conversion_filters -i $(TARGET_SAMPLES)/filter/anim.mkv -i $(TARGET_SAMPLES)/filter/anim-palette.png -lavfi paletteuse=sierra2_4a:diff_mode=rectangle -pix_fmt bgra

76
tests/ref/fate/filter-paletteuse-bayer0 Normal file
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@@ -0,0 +1,76 @@
#tb 0: 1001/24000
#media_type 0: video
#codec_id 0: rawvideo
#dimensions 0: 320x180
#sar 0: 1/1
0, 0, 0, 1, 230400, 0xfb6042d2
0, 1, 1, 1, 230400, 0x1c193c09
0, 2, 2, 1, 230400, 0x183442f8
0, 3, 3, 1, 230400, 0xa9634084
0, 4, 4, 1, 230400, 0x90df3d2f
0, 5, 5, 1, 230400, 0x59d7389f
0, 6, 6, 1, 230400, 0xb9bd3a30
0, 7, 7, 1, 230400, 0x9874ee38
0, 8, 8, 1, 230400, 0xf661f01f
0, 9, 9, 1, 230400, 0xacbcedbd
0, 10, 10, 1, 230400, 0x05f02d59
0, 11, 11, 1, 230400, 0xc54c2cc8
0, 12, 12, 1, 230400, 0x19c92d61
0, 13, 13, 1, 230400, 0x14902fb2
0, 14, 14, 1, 230400, 0x99b62fb6
0, 15, 15, 1, 230400, 0x3fc63293
0, 16, 16, 1, 230400, 0x1eed4b38
0, 17, 17, 1, 230400, 0xe9d747e0
0, 18, 18, 1, 230400, 0x9825496f
0, 19, 19, 1, 230400, 0x94625411
0, 20, 20, 1, 230400, 0xed7052a3
0, 21, 21, 1, 230400, 0x80d552dc
0, 22, 22, 1, 230400, 0x89b360bb
0, 23, 23, 1, 230400, 0xee9a616a
0, 24, 24, 1, 230400, 0x30bb5f86
0, 25, 25, 1, 230400, 0x5ec15eae
0, 26, 26, 1, 230400, 0x0956633e
0, 27, 27, 1, 230400, 0x72df62fa
0, 28, 28, 1, 230400, 0xbafd61d0
0, 29, 29, 1, 230400, 0x393f81f3
0, 30, 30, 1, 230400, 0xba6a848c
0, 31, 31, 1, 230400, 0x502ba0d9
0, 32, 32, 1, 230400, 0xc81ba71d
0, 33, 33, 1, 230400, 0x54cdf270
0, 34, 34, 1, 230400, 0xe951f3e2
0, 35, 35, 1, 230400, 0xbf15baa1
0, 36, 36, 1, 230400, 0xbf96bb12
0, 37, 37, 1, 230400, 0xcdd5cafe
0, 38, 38, 1, 230400, 0x97b1cbb4
0, 39, 39, 1, 230400, 0x955ae28f
0, 40, 40, 1, 230400, 0x6a8dd28f
0, 41, 41, 1, 230400, 0x8f02d268
0, 42, 42, 1, 230400, 0x3075d269
0, 43, 43, 1, 230400, 0x29e8b910
0, 44, 44, 1, 230400, 0xb35ab888
0, 45, 45, 1, 230400, 0xc3afb942
0, 46, 46, 1, 230400, 0xeba8b860
0, 47, 47, 1, 230400, 0x5de8b7ab
0, 48, 48, 1, 230400, 0x90233679
0, 49, 49, 1, 230400, 0x5fbc3abb
0, 50, 50, 1, 230400, 0xeaa73b87
0, 51, 51, 1, 230400, 0xbd0a3c4b
0, 52, 52, 1, 230400, 0xeddb39ba
0, 53, 53, 1, 230400, 0x269d4131
0, 54, 54, 1, 230400, 0xae3e3e8c
0, 55, 55, 1, 230400, 0x65f54056
0, 56, 56, 1, 230400, 0xf2173c5b
0, 57, 57, 1, 230400, 0xbd714477
0, 58, 58, 1, 230400, 0xb60c42ed
0, 59, 59, 1, 230400, 0x8def43a5
0, 60, 60, 1, 230400, 0xe6a73f05
0, 61, 61, 1, 230400, 0xedfe4430
0, 62, 62, 1, 230400, 0x76c5505a
0, 63, 63, 1, 230400, 0xf48d4d04
0, 64, 64, 1, 230400, 0xa49950b5
0, 65, 65, 1, 230400, 0xc64d51d8
0, 66, 66, 1, 230400, 0xa08253ec
0, 67, 67, 1, 230400, 0xd6ef4609
0, 68, 68, 1, 230400, 0x27a241e7
0, 69, 69, 1, 230400, 0xe5f74b4a
0, 70, 70, 1, 230400, 0xb0194751